8250_pci: fix pch uart matching

commit aaa10eb1d0034eccc096f583fe308f0921617598 upstream.

The rules used to make 8250_pci "ignore" the PCH uarts are lacking pci subids
entries, preventing it to match and thus is breaking serial port support for
theses systems.

This has been tested on a nanoETXexpress-TT, which has a specifici uart clock.

Tested-by: Erwan Velu <Erwan.Velu@zodiacaerospace.com>
Signed-off-by: Arnaud Patard <apatard@hupstream.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>